Innovative Method for Water and CO2 Sequestration and Reclamation in Long Duration PLSS

NASA is interested in extending the duration of EVA’s in order to support operations on the Moon and eventually Mars. Mission time requirements will increase in these demanding environments and new challenges will need to be addressed in order to accommodate them. One critical function of the space suite is to maintain the CO2 and water levels in the ventilation loop at acceptably safe levels. With the increased demands of the Lunar and Martian environments, there is a strong need to recover the water and CO2 removed from the ventilation loop oxygen supply. Previously developed control modules have not been designed to accommodate these requirements and thus, there is a need for an improvement in this technology. Reaction Systems intends to develop a new method to control CO2 and water in the xEMU ventilation loop that is capable of recovering the removed products as well as accommodating longer mission times. Reaction Systems will utilize a hollow fiber module to contact the ventilation loop flow from the crewmember against compounds that will rapidly adsorb CO2 and control water to the required levels. The gas flow will be directed through the lumen side of the module and sorbents contained in the liquid phase will be maintained on the shell side of the module. The liquid volume will be large enough to contain the quantity of CO2 and humidity produced in an extended EVA. At the end of the EVA, the liquid phase will be heated to moderate temperature to drive the CO2 out where it can be recovered along with the extra water collected in the liquid phase. In addition to NASA, the market for this technology will include many of the private companies that are investing large amounts of resources to develop their own exploration capabilities. There is also a growing need to identify cost effective methods to control CO2 emitted into the atmosphere, and identifying new sorbents could contribute to this important objective.
Benefits: In addition to its use in the xEMU, this technology could be used for CO2 control in a space craft cabin. The current technology, the CDRA, uses a pressure and temperature swing adsorption cycle to remove CO2. It requires high regeneration temperatures, and the thermal cycling causes the molecular sieve sorbent to break down into dust particles which can clog filters or end up in the cabin air. A liquid sorbent would not require the use of a solid molecular sieve and would also not require high regeneration temperatures. This could increase the lifetime of the system, eliminate dust from the air supply, and reduce the power requirements of the regeneration cycle. This technology could also be used to capture the CO2 from power plant emissions. The CO2 concentration in the atmosphere has increased by close to 50% over the last 50 years primarily due to CO2 emissions from fossil fuel combustion. This technology could be used effectively to remove CO2 from the effluent of these sources in a manner that facilities convenient storage and reclamation of the compound.